lol. i can talk you through this.
An ISO is a mirror of a CD or DVD. Every respectable burning application can burn ISO files. I use dvdSanta which is free and googlable. There is one thing you need to be aware of, that I haven't tried doing with dvdSanta. I have used Nero, though. You open up Nero and look through the New Project Wizard and/or the File/Edit/Tools/etc menus. Look for anything that lets you burn a CD from an ISO file. It should say "Burn from ISO..." or something in the menu, and clicking it should open a dialog box where you can browse your PC for the ISO file you want to use. Just make sure that you make a bootable CD. Again, this shouldn't be very difficult in Nero. In the New Project Wizard you should be able to choose if you are making a data disc, a music disc, a video disc, a bootable disc, etc. If there are two different ones, choose the first one in the ascending order.
When the CD is ready, put it in and reboot your computer. Before Windows starts booting up, the CD should either boot automatically, or text should appear telling you to press any button to boot the CD. If you don't press a button, your PC will neglect the CD and boot Windows from the harddrive anyway. If the CD doesn't boot, and you don't see the aforementioned text, you need to enter your BIOS and change a simple setting. The first screen you see when you start your PC should tell you your amount of RAM, what IDE or SATA devices are connected to your PC, what prosessor you have. Alternatively, a manufacturer logo. Look if it says "Press DEL to enter setup", "Press F2 to enter setup", or whatever it asks you to press to enter setup. In the setup interface, look for the screen that lets you change the boot priority. Choose your CD-ROM as your primary or first boot device, your hard drive as the secondary boot device. Save and exit and reboot again. This time your PC should notify you that there is a bootable CD in your disc drive, and ask you if you want to boot from it. You obviously do
XP setup starts. You are asked whether you want to repair the current installation or install a fresh installation. You don't want to repair. When you choose to install Windows and accept the liscense agreement, you are to pick the harddrive to install it to. If you have one physical hard drive in your computer, but a C:\ and a D:\ in your "My Computer", you have partitions. Maybe you know what they are, I'm not insinuating, but you want to delete the entire C:\ partition. This will create unallocated space on your hard drive. Format this unallocated space and your partition is ready. I don't remember which order these things happen in, but I think you choose the hard drive to install to and accept. Then, on the next screen, you are asked if you want to format the partition before installing or not. Either way, you get the picture of what you need to do.
After that it should all be down-hill. Don't listen to Gotti
You don't need to mount the ISO file in DOS. If I missed a detail and you don't have a burner, I'm sure you have a friend with one. You must at least have a USB stick or some form of portable storage device of more than 1GB to bring the ISO to your friend.